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A231971 Number of (n+1) X (2+1) 0..1 arrays with no element having a strict majority of its horizontal and vertical neighbors equal to one. 1
16, 56, 169, 550, 1764, 5680, 18225, 58596, 188356, 605458, 1946025, 6255180, 20106256, 64627982, 207734569, 667725402, 2146283584, 6898841796, 22175081569, 71277802674, 229109651716, 736431677100, 2367126871209, 7608702637640 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 3*a(n-1) + 2*a(n-3) + 4*a(n-4) - 10*a(n-5) - 2*a(n-6) - a(n-8) + a(n-9).

Empirical g.f.: x*(16 + 8*x + x^2 + 11*x^3 - 62*x^4 - 14*x^5 + x^6 - 5*x^7 + 6*x^8) / ((1 - 3*x - x^2 + x^3)*(1 + x^2 - 3*x^4 - x^6)). - Colin Barker, Oct 01 2018

EXAMPLE

Some solutions for n=2:

..0..0..1....1..0..0....0..0..0....0..0..1....0..0..0....0..0..0....0..0..1

..1..0..0....0..0..1....1..0..1....0..0..0....0..0..0....0..1..0....1..0..0

..0..0..0....0..0..0....1..0..0....0..0..0....0..0..0....0..0..0....1..0..0

CROSSREFS

Column 2 of A231977.

Sequence in context: A039451 A279063 A331766 * A333279 A304692 A295986

Adjacent sequences:  A231968 A231969 A231970 * A231972 A231973 A231974

KEYWORD

nonn

AUTHOR

R. H. Hardin, Nov 16 2013

STATUS

approved

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Last modified June 12 22:34 EDT 2021. Contains 344974 sequences. (Running on oeis4.)